A Newton-based company is in line to receive the contract for the first phase of the Adams Green park project in downtown Quincy.

The state Department of Transportation said A.R. Belli submitted the lowest of five bids for the streets-and-sidewalks phase of the park project, which is expected to start in November. A.R. Belli’s bid was $7.9 million.

The planned Adams Green park, a critical piece of the $1.6 billion downtown redevelopment project, would run between the Church of the Presidents, city hall and Hancock Cemetery. The first phase of the park project calls for wider sidewalks, streetlight and crosswalk improvements, traffic signals, halting southbound traffic on Hancock Street and converting nearby roads from one-way to two-way.

Sara Lavoie, a spokeswoman for the Department of Transportation, said the state plans to offer the contract to A.R. Belli. She said work will likely start in mid-November.

Bill Keaveney, general contractor for A.R. Belli, said construction will be minimal this fall and winter because of the weather.

“There will be some limited underground work,” Keaveney said.

Project planners have said the first phase of Adams Green will be completed by the end of 2015. The portion of Hancock Street between city hall and Church of the Presidents is expected to be closed to traffic sometime in 2014.

The second – and final – phase of Adams Green is the creation of the park itself. That work is to begin in 2014. Planners have estimated that the second phase will cost about $25 million, and the city is still awaiting approval from the state to finance it.

Adams Green is one piece of the downtown redevelopment project, a joint venture between the city of Quincy and private developers Street-Works and Twining Properties. The project, targeted for completion in 2020, is expected to bring 3.5 million square feet of new residential, retail, office, entertainment and educational space to Quincy Center.